This won't be the first 1:72 combat Bismark we've seen. There's a 1:72 club (active and battling) up in Washington and Oregon, and a few of their club members are even down in California. Here's a 1:72 Bismark that visited the WWCC a few years ago:
http://s65.photobucket.com/albums/h237/kotori87/?action=view¤t=IMG_0181.jpg
http://s65.photobucket.com/albums/h237/kotori87/?action=view¤t=IMG_0183.jpg
http://s65.photobucket.com/albums/h237/kotori87/?action=view¤t=IMG_0195.jpg
http://s65.photobucket.com/albums/h237/kotori87/?action=view¤t=IMG_0196.jpg
http://s65.photobucket.com/albums/h237/kotori87/?action=view¤t=IMG_0198.jpg
Pretty impressive, eh? That 1:72 Bismark had four twin 1/4" cannons, gigantic magazines, and two 24-oz CO2 bottles. It required hundreds of pounds of ballast to get it down to waterline, and it could break into two pieces for transport. The problem is, with ships that big, they don't handle worth a darn. That Bismark had poor acceleration and a gigantic turning radius. It needed the entire 1:144 battle area just to turn 180 degrees, and then it ran itself aground. This gave me a pretty good idea why most of the 1:72 battlers stick with destroyers and light cruisers. The battleships are just TOO darned big.
In addition, there are some tactical concerns that the 1:72 battlers have mentioned. In their experiments with heavy cruisers (nobody's actually fought a battleship yet), the plucky destroyer captains discovered that if they got close enough, the bigger ships' guns couldn't aim low enough to hit. They would close to point-blank range (taking a few hits on the way in), and then empty their magazines into the heavy cruiser at point-blank range. Battleships are even more susceptible to this weakness; unless you've got casemate guns very low to the water, any ship that gets close enough will be immune to any weapons you have onboard.
The size issue and the tactical disadvantage apply particularly to the large WWII battleships. They are less applicable to WWI battleships and battlecruisers, and even less so to predreadnought-era ships. I personally believe that, while 1:72 scale is too big for modern battleships, it is perfect for the Predreadnought Era. Predreadnought battleships and Armored Cruisers, along with a few early dreadnoughts, are difficult to do in the more common 1:144 scale, but in 1:72 scale, even predreadnought-era torpedo boats become possible. The Predreadnought Era holds a special place in my heart, and as soon as I graduate, the Big-Gun Predreadnought Revolution shall begin.